In an unusual joint letter presented Monday, the two organizations asked the city to thoroughly research how a new heliport might work, how much it would cost and what the impacts might be.

"It is in the interest of both entities that the city not attempt to go forward with an alternative heliport site without a fully developed record," the letter said. "With that in mind, we ask you to put aside any sense of urgency and to proceed very carefully after gathering all the information needed."

A city-sponsored heliport study last year recommended that satellite heliports at Montana Creek and Dupont, south of Thane, would reduce flightseeing noise in Juneau. A Sheep Creek site also was evaluated in the study. City Manager Dave Palmer has suggested that the city look at a heliport in the Thane area first.

Amy Windred, Era Helicopters' Juneau base manager, said the letter was the result of meetings between her company and Thane residents over the past couple of months.

"One thing we could both agree on is that there's information we need to get before a good decision can be made," she said.

Specifically, Era is interested in how a satellite heliport might work, she said. The letter asks for data about water, sewer, fire protection and cost.

A Thane Neighborhood Association survey this year showed that most residents are opposed to, and have serious concerns about, a satellite heliport in the area. President Larri Spengler said the association would like the city to look at a wide range of sites.

"Let's take our time to see what the effects are, the impacts are, and then make a decision," she said. "There has to be an incremental process of gathering information and weighing it."

The letter also asks for more information about noise impacts, traffic and zoning considerations.

Assembly members have proposed using about $500,000 in passenger fee revenues for heliport research and quiet technology this year, although a decision hasn't been made. The Assembly also has asked the federal government for funds to prepare an heliport environmental assessment, Assembly member Dale Anderson said.

"It will have to look at the environmental issues, the social issues, and it will have to come up with a much more detailed cost of construction of the facilities, but also the cost of access," he said. "We are going to take it judiciously and with the entire community in mind."